CD22, a B lymphocyte-specific adhesion molecule that regulates antigen receptor signaling

Annu Rev Immunol. 1997;15:481-504. doi: 10.1146/annurev.immunol.15.1.481.


The development of B lymphocytes is a highly regulated process that depends in part on lineage-specific cell surface molecules. In addition, transmembrane signals generated through the B cell antigen receptor and other surface molecules regulate B cell responses to foreign antigens. Recent studies reveal CD22 to be a functionally significant receptor during these processes. CD22 is first expressed in the cytoplasm of pro-B and pre-B cells, and on the surface as B cells mature to become IgD+. CD22 is a member of the Ig superfamily that serves as an adhesion receptor for sialic acid-bearing ligands expressed on erythrocytes and all leukocyte classes. In addition to its potential role as a mediator of intercellular interactions, signal transduction through CD22 can activate B cells and modulate antigen receptor signaling in vitro. CD22 signaling is mediated via interactions with a number of kinases and phosphatases that bind the cytoplasmic domain through phosphorylated tyrosine residues located within consensus TAM and TIM motifs. The phenotype of CD22-deficient mice suggests that CD22 is primarily involved in the generation of mature B cells within the bone marrow, blood, and marginal zones of lymphoid tissues. Most notable in CD22-deficient mice is a significant diminution of surface Ig levels in these B cell subpopulations, which suggests that CD22 functions in vivo to adjust the signaling threshold of cell surface antigen receptors. A further understanding of CD22 function is required and may reveal roles for CD22 in disease susceptibility or the development of autoimmunity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigens, CD / chemistry
  • Antigens, CD / genetics
  • Antigens, CD / metabolism*
  • Antigens, Differentiation, B-Lymphocyte / chemistry
  • Antigens, Differentiation, B-Lymphocyte / genetics
  • Antigens, Differentiation, B-Lymphocyte / metabolism*
  • B-Lymphocytes / immunology*
  • Carbohydrate Sequence
  • Cell Adhesion Molecules / chemistry
  • Cell Adhesion Molecules / genetics
  • Cell Adhesion Molecules / metabolism*
  • Chromosome Mapping
  • Humans
  • Lectins*
  • Ligands
  • Mice
  • Molecular Sequence Data
  • Molecular Structure
  • Receptors, Antigen, B-Cell / metabolism*
  • Sequence Homology, Amino Acid
  • Sialic Acid Binding Ig-like Lectin 2
  • Signal Transduction


  • Antigens, CD
  • Antigens, Differentiation, B-Lymphocyte
  • CD22 protein, human
  • Cd22 protein, mouse
  • Cell Adhesion Molecules
  • Lectins
  • Ligands
  • Receptors, Antigen, B-Cell
  • Sialic Acid Binding Ig-like Lectin 2